Casey Anthony, right, with defense attorney Jose Baez, listens to proceedings during her murder trial at the Orange County Courthouse, in Orlando, Fla., Wednesday, June 15. Anthony, 25, is charged with killing her 2-year old daughter in 2008.

Prosecutors in the trial of Casey Anthony, the Florida mother charged with killing her 2-year-old daughter, Caylee, have left fundamental questions about the crime unresolved, even as they announced on Wednesday that the state was resting its case.

The answers to these questions may not be critical for the seven women and five men on the jury to ultimately render a guilty verdict. But given that the Orange County State Attorney’s Office is seeking to have Ms. Anthony put to death by lethal injection, those questions would almost certainly arise during lengthy appeals.

Prosecutors are presenting a theory, based on circumstantial evidence, that Anthony drugged her daughter with chloroform and then smothered her by pressing three pieces of duct tape over her mouth and nose before hiding her body in the trunk of her car and later dumping it in a wooded area.

Presented with gruesome images of Caylee’s skull and skeletal remains, jurors have also been shown photographs of Anthony and Caylee playing happily together, smiling, and laughing. Witnesses testified that Anthony was a responsible, attentive mother.

There is a disconnect at the center of the case. Who is Casey Anthony – a caring mother, a cold-hearted killer – or both?

The trial has attracted a cult-like following of amateur sleuths across the country. Part of the attraction is the growing sense of mystery surrounding the entire messy saga. Testimony during the government’s portion of the trial has only deepened the mystery.

Nothing seems to add up.

Why would a mother wait 31 days before telling her friends, family, or the police that her toddler was missing and allegedly kidnapped by her nanny?

How could a mother whose child had recently died – or worse, was killed by her – pretend that nothing had happened by partying with friends, staying with her new boyfriend, and going on shopping excursions?

What motive would a young mother have to kill her daughter rather than simply ask her parents, Cindy and George Anthony – who adored Caylee – to care for the child, or place her for adoption?

Another scenario

Some analysts have suggested Caylee might have died an accidental death and that Casey Anthony could not bear to admit the tragedy to her mother. Instead, according to this scenario, she hid the body, first in her car and later, once it started to decompose and smell, in the woods near the family’s house.

Anthony had acted in a similar fashion before. About three years earlier, she had exhibited extreme reluctance to tell her mother some shocking news. Casey was seven months pregnant with Caylee before her mother noticed that her daughter’s expanding girth was more than just menstrual bloating, according to Cindy Anthony’s trial testimony.

Defense lawyers have suggested Caylee’s death was accidental, but the details of their scenario are highly unusual. They say the toddler died in the swimming pool and was found by both George Anthony and Casey. Rather than call 911, the father and daughter tried to cover up the death by hiding the body. The father-daughter connection was further complicated, defense lawyers say, by a history of sexual abuse.

Despite years of investigation and a massive effort to solve one of the nation’s highest-profile cases, state prosecutors have been unable to introduce a single piece of direct evidence linking Anthony to the murder of her daughter.

In addition, there has been no evidence or testimony suggesting Anthony had ever harmed or mistreated her daughter.

Instead, prosecutors have built their case around circumstantial evidence that they say points inexorably to Anthony’s guilt.

Hair

A single nine-inch strand of hair was found in the trunk of Casey’s car. According to an FBI forensic expert it was consistent with Caylee’s hair and showed signs that it might have come from a decomposing body. The hair evidence is important because it suggests that someone may have placed Caylee’s dead body in the trunk of Casey’s car.

But studies are inconclusive about whether hair is a reliable indicator of a dead body. In addition, even if Caylee’s body was in the car there is no evidence of who placed it there. Prosecutors assume that since it was Casey’s car anything in the trunk would have to have been placed there by her.

Smell

Several witnesses testified that they noticed a strong, distinctive stench in Casey’s car in the summer of 2008. Several witnesses said it smelled like a decomposing human body. A research scientist at the Oak Ridge National Laboratory who has studied human decomposition for 20 years testified that the stench in the trunk was the unmistakable odor of human decomposition.

Chloroform

The same research scientist measured air and carpet samples in the trunk of Casey’s car and found unusually high levels of chloroform. Investigators also discovered that someone had performed an Internet search on a home computer during two days in March 2008 concerning chloroform and how to make chloroform. The searches were performed during times when Casey Anthony’s parents were out of the house at work and she could have been home alone with Caylee.

There is no indication that chemicals were purchased and mixed, or how or where they might have been purchased and mixed. In addition, tests performed on Caylee’s bones showed no presence of chloroform or other toxic substances or drugs.

Duct tape

Prosecutors say the murder weapon was three pieces of duct tape that were recovered near Caylee’s skeletal remains on Dec. 11, 2008. They were each six to eight inches long and investigators suspect they were placed over Caylee’s nose and mouth, causing suffocation.

FBI forensic experts found no fingerprints on the tape, but it was the same distinctive brand of duct tape that was used on a gas can in a shed at the Anthony home and was used by George Anthony to display a poster during an earlier search for Caylee.

There is no indication that Casey ever handled the duct tape or knew where it was, but she might have had access to it in the house or garage. In addition, there is no evidence proving that the duct tape was affixed to Caylee’s face in a way that blocked both her mouth and nose.

The bags

Caylee’s remains were found partly contained in two black plastic garbage bags and a canvas laundry bag. Similar garbage bags were found by investigators in the Anthony’s garage, and Cindy Anthony testified that the same model of canvas laundry bag had also been stored in the garage. Casey might have had access to the bags, but there is no evidence that she actually used them.

Heart-shaped stickers

An FBI fingerprint expert says she saw the adhesive outline of what might have been a heart-shaped sticker on one of the pieces of duct tape found near Caylee’s remains. The expert continued testing for fingerprints, but when she returned to photograph the heart-shaped object, she says she could no longer see it.

Crime scene investigators also located a piece of cardboard in the vicinity of Caylee’s remains containing a heart-shaped sticker. Investigators found heart-shaped stickers in a drawer in Casey’s bedroom, but they did not appear to be the same size as the purported duct tape image.

Lying

Casey told frequent lies to her friends and family in the weeks after Caylee disappeared in mid-June 2008. When asked about Caylee, she told them the toddler was with her nanny. Sometimes she suggested she was planning future events with her daughter, including an approaching birthday in August.

After Caylee’s disappearance was reported to police, Casey told them that the toddler was with her nanny who had kidnapped the child. No nanny was ever found. Casey also lied to police about her employment. When her stories did not check out, police began to shift their focus toward Casey.

Medical examiner

The Orange County Medical Examiner said she was unable to determine the cause of Caylee’s death because her remains had been reduced to a skeleton by the time they were found. Nonetheless, she said she could classify her death as a homicide.

“There is no child that should have duct tape on its face when it dies,” Dr. Jan Garavaglia said. She was careful to add that she was not speculating that death was caused by the tape. On cross-examination she was asked how she could be certain Caylee’s death was not an accident. Dr. Garavaglia said that by a “preponderance of evidence” homicide was the “only logical conclusion.”